1. Field of Disclosure
Embodiments of the disclosure relate generally to techniques for separating whole blood, and more particularly to a system and method utilizing a rotor and a centrifuge to separate whole blood into plasma and blood cell fractions, as well as other complex fluids.
2. Discussion of Related Art
The use of rotors or discs and centrifuges to separate whole blood is well known. The rotor is configured to receive a sample of whole blood, and upon the performance of a centrifuge operation, plasma is separated from red blood cells. With one known rotor, a sample of whole blood is delivered into a metering chamber through an inlet. The metering chamber includes an overflow channel and a vent. A drain channel connects the metering chamber to a decant region, which comprises two chambers separated from one another such that overflow from a first, separation, chamber spills into a second, plasma, chamber. The arrangement is such that when a centrifuge operation takes place, whole blood travels from the metering chamber to the separation chamber by way of the drain channel. The spinning of the rotor results in red blood cells being separated from the whole blood so that the red blood cells are disposed at the bottom of the first, separation chamber. Once completely separated, plasma rests on top of the red blood cells, and any excess plasma provided in the first chamber spills into the second chamber. One limitation of this type of rotor is that it does not provide a mechanism for withdrawal of the plasma from the rotor.
Other rotor designs suffer from the same limitation as the aforementioned rotor design. The plasma is trapped within the rotor, with no mechanism to withdraw the plasma after it has been isolated. Another difficulty presented by some rotor designs is that a seal may be required between a device, such as a pipette, used to inject whole blood into the rotor and to extract plasma from the rotor. Thus, these rotors do not interface with traditional liquid handling systems, such as those used for diagnostic testing. With nearly all rotors, the plasma must be moved to a second chamber prior to use. Moreover, most rotors use hydrophilic and/or hydrophobic patterning or some other type of valve to control red blood cell and plasma separation.